Question

我想将查询的结果转换为js中的树对象，查询的每个字段都是在js文件中像['field2', 'field3']这样的数组中添加的，因此后端使用它必须在最内部字段的最外部（从左到右）创建树（查询也由字段的ID分组），这是查询（请记住，字段是动态的，因此添加了更多字段），树的最后一个分支应该是数量（也是动态的）

SELECT 
    T2.field2 as field2, T3.field3 as field3, SUM(quantity) AS quantity
FROM 
    table1 T1
    INNER JOIN
    table2 T2 ON T1.table2_id = T2.id
    INNER JOIN
    table3 T3 ON T1.table3_id = T3.id
WHERE
    AND T1.date = 20190611
GROUP BY T1.table2_id, T1.table3_id

这将为我提供一组这样的数据

'Group 1', 'Data 0', '9172'
'Group 1', 'Data 1', '789'
'Group 1', 'Data 22', '289'
'Group 1', 'Data 3', '254'
'Group 1', 'Data 4', '197'
'Group 1', 'Data 55', '173'
'Group 2', 'Data 0', '38'
'Group 2', 'Data 11', '3'
'Group 2', 'Data 4', '4'
'Group 3', 'Data 0', '807'
'Group 3', 'Data 1', '40'
'Group 3', 'Data 18', '4'
'Group 3', 'Data 2', '35'

我需要做的就是将其转换为这样的图形。

[
  {
    field2: 'Group 1',
    data: [
      {
        field3: 'Data 0',
        data: [
          { quatity: 9172 },
        ],
      },
      {
        field3: 'Data 1',
        data: [
          { quatity: 789 },
        ],
      },
      {
        field3: 'Data 3',
        data: [
          { quatity: 289 },
        ],
      },
      {
        field3: 'Data 4',
        data: [
          { quatity: 197 },
        ],
      },
      {
        field3: 'Data 55',
        data: [
          { quatity: 173 },
        ],
      },
    ],
  },
  {
    field2: 'Group 2',
    data: [
      {
        field3: 'Data 0',
        data: [
          { quatity: 38 },
        ],
      },
      {
        field3: 'Data 11',
        data: [
          { quatity: 3 },
        ],
      },
      {
        field3: 'Data 4',
        data: [
          { quatity: 4 },
        ],
      },
    ],
  },
  {
    field2: 'Group 3',
    data: [
      {
        field3: 'Data 0',
        data: [
          { quatity: 807 },
        ],
      },
      {
        field3: 'Data 1',
        data: [
          { quatity: 40 },
        ],
      },
      {
        field3: 'Data 18',
        data: [
          { quatity: 4 },
        ],
      },
      {
        field3: 'Data 2',
        data: [
          { quatity: 35 },
        ],
      },
    ],
  },
]

这里的窍门是查询中的字段是动态的，因此我需要谨慎查看直到到达列表中的最后一个字段，因此，如果字段数组中有['field2', 'field3', 'field4']之类的项和值数组有一个像['quantity', 'balance']这样的数组结果应该是类似

[
  {
    field2: 'Group 1',
    data: [
      {
        field3: 'Data 0',
        data: [
          {
            field4: 'Last field,
            data: [
              { quantity: 3435, balance: 43.53 },
            ],
          },
          {
            field4: 'Last field,
            data: [
              { quantity: 234, balance: 241.53 },
            ],
          },
        ],
      },
    ],
  },
]

如何实现这一目标？

Answer 1

您可以通过使用keys and values数组来采用组合方法并查找相同的对象。

var data = [['Group 1', 'Data 0', '9172'], ['Group 1', 'Data 1', '789'], ['Group 1', 'Data 22', '289'], ['Group 1', 'Data 3', '254'], ['Group 1', 'Data 4', '197'], ['Group 1', 'Data 55', '173'], ['Group 2', 'Data 0', '38'], ['Group 2', 'Data 11', '3'], ['Group 2', 'Data 4', '4'], ['Group 3', 'Data 0', '807'], ['Group 3', 'Data 1', '40'], ['Group 3', 'Data 18', '4'], ['Group 3', 'Data 2', '35']],
    keys = ['field2', 'field3'],
    values = ['quantity'],
    result = data.reduce((r, a) => {
        keys
            .reduce((q, k, i) => {
                var temp = q.find(o => o[k] === a[i]);
                if (!temp) q.push(temp = { [k]: a[i], data: [] });
                return temp.data;
            }, r)
            .push(Object.assign({}, ...values.map((k, i) => ({ [k]: a[keys.length + i] }))));
        return r;
    }, []);

console.log(result);

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将分组查询转换为对象树

1 个答案: